Evolution and humans: recent cave studies (Evolution)

Comment: Glaciers had come with cold temperature. They lived in caves. Their clothing was animal skins. They had simple language, simple social rules, sndf brains gaht had jumped 200,000 cc ove 150,000 years before and they hardly knew how to use that capacity. They learned in the past 12,000 years and the brain shrunk. Size first, use second, obviously in each staged jump in size.

dhw: Yes, their life was simple compared to ours, and that is why the brain did not require further changes. The earliest known clothes go back 170,000 years (they could go back further). Give or take a few thousand, this and other advances may have caused the last expansion. Then humans continued to use that capacity until 12,000 years ago it could not cope with an explosion of new concepts. The fact that densification is CAUSED by new concepts clearly suggests that conceptualization causes changes to the brain – expansion in the early days, densification in later times.

DAVID: Let's specify that the clothes were hides, the only coverings available through hunting, again not complex. Let's not fool ourselves. Concepts appeared gradually until recently. The 200 cc jump in size was sudden and not used it was learned how to use it, and then the brain shrunk. You still have it all backwards.

Of course they were hides. And they were acquired by hunting. A quick google suggests that the first spears may even go back as many as 500,000 years. Name me one other animal that invents and makes weapons. Later came the use of hides as protection against the climate. Name me one other animal that cuts off the skin of another to protect itself. New concepts are new concepts, no matter how primitive they may seem to you, and each one may demand specialized use of the brain. Reading was a new concept to the illiterate women, and their brains responded to the new need by rewiring themselves, and so just as muscles respond to exercise by expanding, the brain would have done the same until it could no longer expand. Then, when it needed new abilities 12,000 years ago, it densified instead of expanding. I'm only theorizing of course, but can you fault the logic?